title: Suboptimal adherence to doxycycline and treatment outcomes among men with non-gonococcal urethritis: a prospective cohort study.
abstract: OBJECTIVE
  Doxycycline, one of two recommended therapies for non-gonococcal urethritis (NGU), consists of a 7-day course of therapy (100 mg BID). Since suboptimal adherence may contribute to poor treatment outcomes, we examined the association between self-reported imperfect adherence to doxycycline and clinical and microbiologic failure among men with NGU.
  
  
  METHODS
  Men aged ≥16 years with NGU attending a Seattle, WA, sexually transmitted diseases clinic were enrolled in a double-blind, parallel-group superiority trial from January 2007 to July 2011. Men were randomised to active doxycycline/placebo azithromycin or placebo doxycycline/active azithromycin. Imperfect adherence was defined as missing ≥1 dose in 7 days. Urine was tested for Chlamydia trachomatis (CT), Mycoplasma genitalium (MG), and Ureaplasma urealyticum-biovar 2 (UU-2) using nucleic acid amplification tests. Clinical failure (symptoms and ≥5 PMNs/HPF or discharge) and microbiologic failure (positive tests for CT, MG, and/or UU-2) were determined after 3 weeks.
  
  
  RESULTS
  184 men with NGU were randomised to active doxycycline and provided data on adherence. Baseline prevalence of CT, MG and UU-2 was 26%, 13% and 27%, respectively. 28% of men reported imperfect adherence, and this was associated with microbiologic failure among men with CT (aRR=9.33; 95% CI 1.00 to 89.2) and UU-2 (aRR=3.08; 95% CI 1.31 to 7.26) but not MG. Imperfect adherence was not significantly associated with clinical failure overall or for any specific pathogens, but it was more common among imperfectly adherent men with CT (aRR=2.63; 0.93-7.41, p=0.07).
  
  
  CONCLUSIONS
  Adherence may be important for microbiologic cure of select pathogens. Factors other than adherence should be considered for CT-negative men with persistent NGU.
authors.affiliation: Department of Epidemiology, University of Washington, , Seattle, Washington, USA.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Khosropour
authors.forename: Lisa E
authors.initials: LE
authors.lastname: Manhart
authors.forename: Danny V
authors.initials: DV
authors.lastname: Colombara
authors.forename: Catherine W
authors.initials: CW
authors.lastname: Gillespie
authors.forename: M Sylvan
authors.initials: MS
authors.lastname: Lowens
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Totten
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Golden
authors.forename: Jane
authors.initials: J
authors.lastname: Simoni
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000009:adverse effects; D017963:Azithromycin / Q000008:administration & dosage* / Q000009:adverse effects; D002690:Chlamydia Infections / Q000188:drug therapy / Q000652:urine; D015331:Cohort Studies; D004318:Doxycycline / Q000008:administration & dosage* / Q000009:adverse effects; D006801:Humans; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D009175:Mycoplasma Infections / Q000188:drug therapy / Q000652:urine; D021141:Nucleic Acid Amplification Techniques; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D012044:Regression Analysis; D017211:Treatment Failure; D016869:Ureaplasma Infections / Q000188:drug therapy / Q000652:urine; D014526:Urethritis / Q000188:drug therapy*; D014556:Urine / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin; D004318:Doxycycline
keywords: ADHERENCE; ANTIBIOTICS; CHLAMYDIA INFECTION; URETHRITIS